An integrated circuit includes an electronic circuit which is situated on a semiconductor substrate and accommodated in a housing having contact elements. Different housings having different contact elements are available, depending on a planned application or field of application. The contact elements are usually electrically connected to corresponding contact elements of a circuit board using a soldering process. The circuit board usually connects the integrated circuit to additional electronic components.
In vehicle electrical systems, for example, it is often necessary to ensure that the electrical connection between the corresponding contact elements is inspected after the soldering process, for example when a security-relevant system is affected, such as a brake control system. The inspection may be carried out visually, for example. If the solder joints are not immediately visible, as is the case, for example, in a QFN or LGA housing, an inspection may be carried out with the aid of x-ray light. However, this is cost-intensive and may produce ambiguous results if other elements, a bonding wire, for example, is visible in the x-ray image. Alternatively, the reliability of the soldering process may be ensured, for example, by providing the contact elements with solder prior to the soldering process. A so-called presoldering process of this type also generates additional costs.
An object of the present invention is therefore to provide a cost-effective solder joint inspection.